1. Field of the Invention
The present invention relates to a non-lethal stun projectile that relies on an electrical impulse to stun the target. More specifically, the present invention relates to a self-contained, non-lethal piezoelectric stun projectile.
2. Description of the Prior Art
Non-lethal neuromuscular disrupter weapons, sometimes referred to as “stun guns”, use a handpiece to deliver a high voltage charge to a human or animal target. The high voltage causes the target's muscles to contract uncontrollably, thereby disabling the target without causing permanent physical damage.
The most well known type of stun gun is known as the TASER gun. TASER guns look like pistols but use compressed air to fire two darts from a handpiece. The darts trail conductive wires back to the handpiece. When the darts strike their target, a high voltage charge is carried down the wire. A typical discharge is a pulsed discharge at 0.3 joules per pulse.
Taser guns and other guns of that type (herein referred to as “neuromuscular disrupter guns” or “NDG's”) are useful in situations when a firearm is inappropriate. However, a shortcoming of conventional NDGs is the need for physical connection between the projectile and the source of electrical power, i.e., the handpiece. This requirement limits the range of the NDG to about 20 feet.
One approach to eliminating the physical connection is to use an ionized air path to the target to create a conductive air path. For example, it might be possible to ionize the air between the handpiece and the target by using high-powered bursts or other air-ionizing techniques. However, this approach unduly complicates an otherwise simple weapon. An example of a NDG that uses conductive air paths to deliver a charge to the target is described in U.S. Pat. No. 5,675,103.
U.S. Pat. No. 5,698,815 describes a stun bullet that does not require a wired connection to the handpiece and which is designed to penetrate the skin of the target and deliver an electrical charge having a lower voltage and lower energy per pulse than typical stun guns. This stun bullet is provided with a battery or alternatively it may have a capacitor to temporarily store a charge delivered to the bullet just prior to firing. The range of this device is said to be well over 100 yards, but the dual dart electrodes must unwind from the bullet to be deployed, and subsequently penetrate the skin. Thus, these projectiles have some disadvantages resulting from the method of deploying the electrodes.
Another approach to providing an NDG that does not require an electrical connection between the handpiece and the projectile is described in U.S. Pat. No. 5,962,806. In this device, an electrical charge is generated within the projectile by means of a battery-powered converter housed within the projectile.
U.S. Patent Nos. 6,679,180; 6,802,261 and 6,802,262 each describe a tetherless neuromuscular disrupter gun employing a liquid-based capacitor projectile. In these patents, the projectile has an outer housing for the liquid and a capacitor is also located within the housing. The gun charges the projectile prior to discharge of the projectile from the gun. Upon impact, the liquid is discharged to deliver a single pulse with sufficient electrical charge to disrupt neuromuscular activity. These projectiles have a limited range of about 60 meters.
There remains a need in the art for a non-lethal approach to stunning or inhibiting a target that does not require electrical contact between the target and a hand-held apparatus, such as a stun gun. In addition what is needed is a single projectile, non-lethal approach to stunning or inhibiting a target that is not range-limited by wires coupled to darts, such as with a TASER, and that can be easily reloaded if an initial firing is unsuccessful.